1. Technical Field
The present invention is generally directed to the removal of burrs, micro slivers, and other surface imperfections from metals. More particularly, the present invention is directed to a multi-directional abrading machine having both abrading drums and abrading discs capable of removing burrs, micro slivers, and similar imperfections in a single, continuous process.
2. Discussion
Bright metal finishes have long been used in automobiles. The use of such finishes has been for both decorative as well as for rust-resistant reasons. Early automobiles incorporated polished brass radiators, hub caps, and other trim components. However, as automobile production increased, the use of brass was found to be too costly for mass production. In response, the automobile industry began to place a metal plating onto a metallic substrate, and many more components were plated. Typical components to be metal plated included radiator shells, door handles, light housings, hub caps, bumpers, and interior fixtures such as knobs and levers.
Early metal plating was nickel. While providing a satisfactory coating, nickel was relatively expensive and provided an inadequate luster. Ultimately, chromium electrodeposits used for decorative purposes were applied as thin coatings over underlying thicker nickel plate. Chromium plating provides considerable superiority over nickel and other plating in both providing a high luster and a high resistance to wear.
Present day chrome and nickel combinations are commonly plated over materials such as steel, brass and zinc-based die castings. Manufacturing of any of these metal composite results in a product that is inherently unsmooth and marred by burrs, micro slivers, and other surface imperfections. Prior to plating these components, the surfaces must be machined so as to remove all of these imperfections, and it is therefore critical that the surface be properly prepared for subsequent plating. Correct bonding between the metal substrate and the plating to be deposited on the substrate is critical, as incorrect adhesion will result in a product that is of poor quality. Specifically, if the substrate is not correctly and completely cleaned of imperfections, the plated material will be prone to peeling, blistering and cracking. While such undesirable qualities may be the result of other problems encountered during the preparation process, the smoothness of the surface plays a critical role in determining the ultimate quality of the final product.
Burrs, micro slivers, and other surface imperfections can often be found at the edges, corners, holes, slots, and other areas of the substrate. In many instances, these burrs, micro slivers, and other imperfections appear on the surface of the component. While burrs and micro slivers on corners, edges, holes and slots can be machined with relative ease by methods including abrasive wheels, discs and drums, the removal of burrs, micro slivers, and similar imperfections from substrate surfaces is typically an arduous and time consuming task.
To make the surface conditioning process simpler, various mechanical processes have been employed to remove the burr or micro sliver from the surface without damaging the adjacent substrate. Mechanical surface conditioning has conventionally been undertaken using grinding media composed virtually entirely of an abrasive grit, cloth, felt or leather, and comprising wheels and belts.
However, known systems for surface conditioning are time consuming and rely on expensive independent components. These systems are time consuming because they require multiple steps of deburring using separate tools, most of which are operated by hand. Furthermore, known systems are expensive because the separate tools are not directed to specific applications for specific components, but are rather tools that are applicable to general deburring. While providing broad-spectrum utility for many applications, known tools fail to provide effective surface conditioning to a specific component, such as an automobile bumper.
Machines to more readily perform the surface conditioning task have been developed. Some of these have specific uses. For example, in U.S. Pat. No. 5,121,572, issued on Jun. 16, 1992 to Hilscher for "Opposed Disc Deburring System," a deburring apparatus is provided having opposed double-disc, counter-rotating abrasive media retaining pads. The component to be deburred is carried through the pads on a turntable having workpiece receiving and guiding bores. As another example, in U.S. Pat. No. 4,373,297, issued on Feb. 15, 1993, to Pennertz et al. for "Deburring Machine", discloses a deburring machine having opposed brushes that drive against a workpiece fixed to a workpiece carriage. The motors may be adjusted to accommodate different lengths of work pieces.
Other inventions directed to the deburring of specific components provide improved levels of automation. For example, U.S. Pat. No. 4,893,642, issued on Jun. 16, 1990 to Parslow, Jr. et al. for "Production Line Part Deburring Apparatus", discloses a part deburring machine that is directed to the deburring of a part having established axes of rotation, such as engine crankshafts, camshafts, vehicle axles and the like. Another example of an automated machine directed to deburring specific components is disclosed in U.S. Pat. No. 5,103,663, issued Apr. 14, 1992 to Shafer et al. for "Dedimpler And Deburring Apparatus." In this patent, a combination dedimpler and deburring apparatus is provided for the dedimpling and deburring of tubes for use in the manufacture of children's toys and lawn furniture.
While representing improvements in the process of surface conditioning, none of the known general methods or specific applications disclosed in the known patents is desirable for the efficient and cost-effective surface conditioning of elongated, substantially planar workpieces such as bumpers.